Magnetic dilution effect and topological phase transitions in (Mn${}_{1-x}$Pb${}_x$)Bi${}_2$Te${}_4$

Abstract

As the first intrinsic antiferromagnetic (AFM) topological insulator (TI), MnBi${}_2$Te${}_4$ has provided a material platform to realize various emergent phenomena arising from the interplay of magnetism and band topology. Here by investigating (Mn${}_{1-x}$Pb${}_x$)Bi${}_2$Te${}_4$ $(0\le x\le 0.82)$ single crystals via the x-ray, electrical transport, magnetometry and neutron measurements, chemical analysis, external pressure, and first-principles calculations, we reveal the magnetic dilution effect on the magnetism and band topology in MnBi${}_2$Te${}_4$. With increasing $x$, both lattice parameters $a$ and $c$ expand linearly by around 2\%. All samples undergo the paramagnetic to A-type antiferromagnetic transition with the N$\acute{e}$el temperature decreasing lineally from 24 K at $x=0$ to 2 K at $x=0.82$. Our neutron data refinement of the $x=0.37$ sample indicates that the ordered moment is 4.3(1)${\mu }_B$/Mn at 4.85 K and the amount of the Mn${}_{\mathrm{Bi}}$ antisites is negligible within the error bars. Isothermal magnetization data reveal a slight decrease of the interlayer plane-plane antiferromagnetic exchange interaction and a monotonic decrease of the magnetic anisotropy, due to diluting magnetic ions and enlarging the unit cell. For $x=0.37$, the application of external pressures enhances the interlayer antiferromagnetic coupling, boosting the N$\acute{e}$el temperature at a rate of 1.4 K/GPa and the saturation field at a rate of 1.8 T/GPa. Furthermore, our first-principles calculations reveal that the band inversion in the two end materials, MnBi${}_2$Te${}_4$ and PbBi${}_2$Te${}_4$, occurs at the $\Gamma$ and $Z$ point, respectively, while two gapless points appear at $x=$ 0.44 and $x=$ 0.66, suggesting possible topological phase transitions with doping.

arXiv comment10 pages, 7 figures

References in corpus (33)

• Maximally-localized generalized Wannier functions for composite energy bands
• Wannier90: A Tool for Obtaining Maximally-Localised Wannier Functions
• Maximally-localized Wannier functions for entangled energy bands
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Prediction and observation of the first antiferromagnetic topological insulator
• Intrinsic magnetic topological insulators in van der Waals layered MnBi${}_2$Te${}_4$-family materials
• Topological axion states in magnetic insulator MnBi${}_2$Te${}_4$ with the quantized magnetoelectric effect
• Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator
• Unique thickness-dependent properties of the van der Waals interlayer antiferromagnet $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$ films
• High-Chern-Number and High-Temperature Quantum Hall Effect without Landau Levels
• Layer Hall effect in a 2D topological Axion antiferromagnet
• Topological Electronic Structure and Its Temperature Evolution in Antiferromagnetic Topological Insulator MnBi2Te4
• Intrinsic magnetic topological insulator phases in the Sb doped MnBi2Te4 bulks and thin flakes
• Spin scattering and noncollinear spin structure-induced intrinsic anomalous Hall effect in antiferromagnetic topological insulator $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$
• A van der Waals antiferromagnetic topological insulator with weak interlayer magnetic coupling
• Natural van der Waals heterostructural single crystals with both magnetic and topological properties
• Variety of magnetic topological phases in the (MnBi${}_2$Te${}_4$)(Bi${}_2$Te${}_3$)${}_m$ family
• Realization of an intrinsic, ferromagnetic topological state in MnBi8Te13
• Evolution of structural, magnetic and transport properties in MnBi2-xSbxTe4
• Maximally localized Wannier functions in LaMnO3 within PBE+U, hybrid functionals, and partially self-consistent GW: an efficient route to construct ab-initio tight-binding parameters for e_g perovskites
• Experimental verification of PbBi${}_2$Te${}_4$ as a 3D topological insulator
• Site Mixing for Engineering Magnetic Topological Insulators
• Crystal and magnetic structures of magnetic topological insulators MnBi${}_2$Te${}_4$ and MnBi${}_4$Te${}_7$
• Magnetic and transport properties in magnetic topological insulators MnBi2Te4(Bi2Te3)n (n=1,2)
• Defect-driven ferrimagnetism and hidden magnetization in MnBi${}_2$Te${}_4$
• Hidden magnetism at the pseudogap critical point of a high temperature superconductor
• Magnetic topological insulator MnBi6Te10 with zero-field ferromagnetic state and gapped Dirac surface states
• Suppression of the antiferromagnetic metallic state in the pressurized MnBi2Te4 single crystal
• Tuning the magnetism and band topology through antisite defects in Sb doped MnBi4Te7
• Pressure-tuned intralayer exchange in superlattice-like MnBi2Te4/(Bi2Te3)n topological insulators
• Growth, characterization and Chern insulator state in MnBi${}_2$Te${}_4$ via the chemical vapor transport method
• Data-driven Exploration of New Pressure-induced Superconductivity in PbBi${}_2$Te${}_4$ with Two Transition Temperatures
• Unconventional pressure-driven metamagnetic transitions in topological van der Waals magnets

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• The electronic structure of Mn${}_{1-x}$Pb${}_x$Bi${}_2$Te${}_4$: experimental evidence of topological phase transition
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